Question: What’s the connection between hurricanes and climate change?

Answer: Hurricanes occur with or without global warming, but global warming has a strong effect on how they behave.

The energy that feeds hurricanes – the name we give tropical cyclones in the North Atlantic – comes from the warmth of ocean water. The oceans absorb over 90% of the excess heat trapped in the atmosphere from rising greenhouse gases [1], so warmer water pumps more energy and moisture into storms once they have formed. This leads to more powerful winds and more rain. Additionally, global warming affects the size of a hurricane – the area it covers – based how deep into the water the excess warmth penetrates [2]. Global warming increases ocean warming not only on the surface, but increasingly farther below it. [3]

Global warming affects another phenomenon called wind shear that could produce fewer Atlantic storms in a given year, [4] but those that persist will become larger, more intense, and longer-lasting than they would otherwise have been. [1] Another wild card is the effect of polar warming on the jet streams, which can alter the path of hurricanes. [5] And finally, sea level rise increases the risk of storm surge and flooding in vulnerable coastal areas exposed to these more powerful hurricanes. [6]

The bottom line is that global warming may result in fewer Atlantic hurricanes but those that form are expected to be larger, wetter, and longer-lived, making them more destructive when they make landfall.